Intracavity spectroscopy with Ti3+:Al2O3 lasers pumped by short pulses

An effective and simple intracavity laser spectroscopy method is proposed and investigated. This method is based on the feasibility of a considerable increase in the duration of lasing and of control of this duration within wide limits in systems with a longitudinal relaxation time considerably longer than the duration of pumping. The results of an experimental investigation show that the use of a Ti³⁺:Al₂O₃ laser can enhance additionally (by a factor of 10², which may be increased to ~10³) the sensitivity of this method, compared with extracavity absorption spectroscopy. The sensitivity control interval was 10^–4 — 10^–5 cm^–1. A distinguishing feature of the method is the use of a special algorithm for the processing of signals in order to eliminate the influence of strong fluctuations of the laser radiation energy (duration).